Personal computers usually have voltage adjustment systems to provide different working voltages to different components of the computer. The voltage adjustment system includes a control module, an adjustment module, and a load module. The adjustment module outputs a constant voltage to the load module via the control module. However, the adjustment module and the control module cannot adjust the voltage according to states of the load module. Thus, when the load module is over-loaded or under-loaded, the adjustment module still outputs the constant voltage, which wastes electric power.
Therefore, there is a need for improvement in the art.